Home DIY

Thanks, is a 115mm a small angle grinder?

but other side of the supply is still at 230V per phase and has a neutral .

Nae neutral here!

Also, this is some of the cable with the translucent painted cores.

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Big difference between the pragmatic answer, that the neutral is derived from earth where the supply enters your house, and the real world answers. The neutral is a return path for current. You would absolutely need to sleeve the neutral with yellow/green sleeving at the visible ends to have a chance of passing regulations. I'm struggling to see what danger it poses to anyone encountering the wiring along it's run.

One thing it might change is resistance which might affect breaker operation, my guess is that would be too small to have that effect though.

It's not something that professional electricians are going to recommend you do though. Lingering in the back of my mind is the worry that the cable may break down further or you may have a bigger risk of a live screw or nail somewhere.

Lastly the regs probably don't permit it somewhere.

Theres continuity between the grey (used as a neutral and the earth) so assumed i pinched it.

Is that tested with both ends of the suspect length of cable disconnected.
Has the inner (grey) insulation been nicked on either end, when the outer was stripped or a stray strand in a junction box, shorting grey to earth

mass is your friend

This is indeed what my friend the consulting engineer told me. There are many soundproofing systems, it seems, all variants on some kind of composite board with a layer of damping. The hard bit is to get the owner above to fetch in his pocket and do the right thing.

Yeah - i remember when pulling the cable through holes in the roof joists that i pinched it - i was too lazy/fucked off with life at the time to properly check so i'm assuming i broke the outer insulation and the grey cables insulation which means its now touching the earth.

@Nef - my worry is yours - the cable is looped under PIR insulation sandwiched between it and the ceiling - so my mind thinks fire risk?

I really can't bring myself to re-do the ceiling though

there is a lesson here somewhere

In theory you could insulation resistance test the individual cores and try and establish which ones are sound, but i can’t recommend it in good faith. You wouldn’t risk using a pipe you knew you had cracked just because you couldn’t see it leaking.

You shouldn’t use the uninsulated earth as a live conductor, even though you do see it. The sheath isn’t rated for use as insulation. And every point of the installation should be earthed.

Can’t really advise what I’d do without seeing the layout of the place. Is there no chance you could pull a new cable through using the old one?

my friendly electrician did that for me and it's only the grey which is bad. I didn't want to make him feel uncomfortable with these sorts of questions so thought i'd rely on the anonymity of a forum instead...

i could run a new cable - but it would mean cutting a section of the ceiing out and then running again in the same holes (the cable runs perpendicular to the joists). probably my only option if we want a fan to run without being a stupid risk.

You can't pull a new cable with the old one? The old one's plastered/stuck to something?

Is there a general rule for how close to the edge of a piece of wood you can drill a hole and screw through?

Like half the narrowest profile in from the edge, or something like that?

Depends on the wood, the screw, what the screw is going into, how tight you do it, countersunk or pan head, if it’s solid timber are you close to the end grain or long grain…

If I’m putting boxes together I set the screw in 10mm, usually slightly more than half the thickness of the board it’s going into the edge of. Mostly birch ply, valchromat or hardwoods, and usually a counterbored hole that will be plugged.

Yeah that's what I feared.

Cheers.

What you screwing to what?

45x45mm upright posts to a 145mm wood face.

With a proper pilot hole (~3mm for 4 or 5mm screws) you should be fine 10mm from the edge. Do a test of course.

I'm looking at buying one of these to put at the front of my basement, venting out through an air brick. There is plenty of room under the door at the top of the stairs which is often left open anyway.

Aim is to combine the above with a dehumidifier to make the basement more usable as a storage space for bikes etc. It's not bad but could be drier and gets water ingress when there is very heavy rain.

Any thoughts?

I'm not too worried. It was more as I was thinking about screw location /number of screws I wondered if there was a general rule or some old school saying.

Any thoughts?

You still might need something to deal with the aroma 😉

Haha, yeah.
It is obviously designed for another purpose, but I figure sometimes sub cultures develop better alternatives to the standard. From what I can find, a bathroom fan would be a bit under powered and inline units designed for attics and multiple vents lack a moisture sensor/controls, are louder and more expensive.

I'm all for it. As someone with no valuable insight, it sounds like a sensible way to get air flow the right way. Otherwise you risk creating a dry room that then sucks moisture from outside. I'd guess in the UK external humidity is greater than internal humidity, but you'll still have the moist air in the house cooling and sinking to the basement. Hopefully that is taken care of by the dehumidifier.

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yes.

Just get sharpies and bin when done, tracers are too expensive.

Any advice for hunting lead flashing issues?

I'm assuming some bricks are sponging water from one side of the roof as the damp stain appears lower down the wall (halfway down in the loft space). I can also see what looks like badly overlapped lead sections.

Anyone got any tips? Or do I have to climb on the roof and randomly investigate?

No tips, but, be warned, it may not be as simple as you think. Nephew has had a similar problem and it took ages to find the actual leak - it was no where near where the damp patch was inside. Water is difficult to track. But, you may be luckier.